Wind farm visual impact assessment – part 3
wind farms
An exploration of methods for assessing the visual impact of proposed wind farms, in several parts. In this post we scale up computation of compound viewsheds to encompass entire wind farms.
Warning
The viewshed maps on this page are very detailed and may take quite a while to display in many web browsers, and may not render at all on small devices such as smartphones or tablets. They are provided purely for development purposes, and final versions will be optimised for faster display.
Introduction
In the previous post in this series we considered compound viewsheds formed from the individual, independent viewsheds of just three of the proposed Palings Yard wind turbines, for illustrative purposes. Now we will scale up those computations to all 47 of the proposed Palings Yard turbines. This has to be done iteratively because all 47 individual viewsheds cannot fit in main memory at once.
Calculating compound viewsheds for larger numbers of wind turbine
In this step, we will calculate the cumulative viewshed for all of the 242 turbines proposed for the Pines wind farm, assuming each one is 260m tall near the tip of the blade.
We can examine the distribution of the number of turbines visible from each pixel in the cumulative viewshed raster. Note that zero turbines are visible from the vast majority of pixels – these have been excluded from the histogram shown below.
The map below shows the cumulative viewshed (with Earth curvature and atmospheric refraction corrections) for all 242 of the proposed Pines wind turbines, each 260m tall near the tip of the uppermost blade, at the indicated positions. The compound viewshed is shaded by the number of turbines visible from each point on the map.